cli: inline write/remove_config_value_to/from_file()

They are short, and it wouldn't make much sense to do load, mutate one entry,
and save in one function.

In later patches, "jj config set"/"unset" will be changed to reuse the loaded
ConfigLayer if the layer can be unambiguously selected.

cli/src/commands/config/mod.rs

@@ -21,6 +21,7 @@ mod unset;
 
 use std::path::Path;
 
+use jj_lib::config::ConfigFile;
 use jj_lib::config::ConfigSource;
 use tracing::instrument;
 
@@ -83,6 +84,18 @@ impl ConfigLevelArgs {
             panic!("No config_level provided")
         }
     }
+
+    fn edit_config_file(&self, config_env: &ConfigEnv) -> Result<ConfigFile, CommandError> {
+        let path = self.new_config_file_path(config_env)?;
+        if path.is_dir() {
+            return Err(user_error(format!(
+                "Can't set config in path {path} (dirs not supported)",
+                path = path.display()
+            )));
+        }
+        let source = self.get_source_kind().unwrap();
+        Ok(ConfigFile::load_or_empty(source, path)?)
+    }
 }
 
 /// Manage config options

cli/src/commands/config/set.rs

@@ -23,11 +23,10 @@ use tracing::instrument;
 use super::ConfigLevelArgs;
 use crate::cli_util::CommandHelper;
 use crate::cli_util::WorkspaceCommandHelper;
-use crate::command_error::user_error;
+use crate::command_error::user_error_with_message;
 use crate::command_error::CommandError;
 use crate::complete;
 use crate::config::parse_toml_value_or_bare_string;
-use crate::config::write_config_value_to_file;
 use crate::ui::Ui;
 
 /// Update config file to set the given option to a given value.
@@ -53,13 +52,7 @@ pub fn cmd_config_set(
     command: &CommandHelper,
     args: &ConfigSetArgs,
 ) -> Result<(), CommandError> {
-    let config_path = args.level.new_config_file_path(command.config_env())?;
-    if config_path.is_dir() {
-        return Err(user_error(format!(
-            "Can't set config in path {path} (dirs not supported)",
-            path = config_path.display()
-        )));
-    }
+    let mut file = args.level.edit_config_file(command.config_env())?;
 
     // TODO(#531): Infer types based on schema (w/ --type arg to override).
     let value = parse_toml_value_or_bare_string(&args.value);
@@ -72,7 +65,10 @@ pub fn cmd_config_set(
         check_wc_author(ui, command, &value, AuthorChange::Email)?;
     };
 
-    write_config_value_to_file(&args.name, value, config_path)
+    file.set_value(&args.name, value)
+        .map_err(|err| user_error_with_message(format!("Failed to set {}", args.name), err))?;
+    file.save()?;
+    Ok(())
 }
 
 /// Returns the commit of the working copy if it exists.

cli/src/commands/config/unset.rs

@@ -19,9 +19,9 @@ use tracing::instrument;
 use super::ConfigLevelArgs;
 use crate::cli_util::CommandHelper;
 use crate::command_error::user_error;
+use crate::command_error::user_error_with_message;
 use crate::command_error::CommandError;
 use crate::complete;
-use crate::config::remove_config_value_from_file;
 use crate::ui::Ui;
 
 /// Update config file to unset the given option.
@@ -39,13 +39,13 @@ pub fn cmd_config_unset(
     command: &CommandHelper,
     args: &ConfigUnsetArgs,
 ) -> Result<(), CommandError> {
-    let config_path = args.level.new_config_file_path(command.config_env())?;
-    if config_path.is_dir() {
-        return Err(user_error(format!(
-            "Can't set config in path {path} (dirs not supported)",
-            path = config_path.display()
-        )));
+    let mut file = args.level.edit_config_file(command.config_env())?;
+    let old_value = file
+        .delete_value(&args.name)
+        .map_err(|err| user_error_with_message(format!("Failed to unset {}", args.name), err))?;
+    if old_value.is_none() {
+        return Err(user_error(format!(r#""{}" doesn't exist"#, args.name)));
     }
-
-    remove_config_value_from_file(&args.name, config_path)
+    file.save()?;
+    Ok(())
 }

cli/src/commands/git/mod.rs

@@ -24,7 +24,8 @@ pub mod submodule;
 use std::path::Path;
 
 use clap::Subcommand;
-use jj_lib::config::ConfigNamePathBuf;
+use jj_lib::config::ConfigFile;
+use jj_lib::config::ConfigSource;
 
 use self::clone::cmd_git_clone;
 use self::clone::GitCloneArgs;
@@ -46,7 +47,6 @@ use crate::cli_util::CommandHelper;
 use crate::cli_util::WorkspaceCommandHelper;
 use crate::command_error::user_error_with_message;
 use crate::command_error::CommandError;
-use crate::config::write_config_value_to_file;
 use crate::ui::Ui;
 
 /// Commands for working with Git remotes and the underlying Git repo
@@ -114,12 +114,10 @@ fn write_repository_level_trunk_alias(
     remote: &str,
     branch: &str,
 ) -> Result<(), CommandError> {
-    let config_path = repo_path.join("config.toml");
-    write_config_value_to_file(
-        &ConfigNamePathBuf::from_iter(["revset-aliases", "trunk()"]),
-        format!("{branch}@{remote}").into(),
-        &config_path,
-    )?;
+    let mut file = ConfigFile::load_or_empty(ConfigSource::Repo, repo_path.join("config.toml"))?;
+    file.set_value(["revset-aliases", "trunk()"], format!("{branch}@{remote}"))
+        .expect("initial repo config shouldn't have invalid values");
+    file.save()?;
     writeln!(
         ui.status(),
         r#"Setting the revset alias "trunk()" to "{branch}@{remote}""#,

cli/src/config.rs

@@ -22,7 +22,6 @@ use std::path::PathBuf;
 use std::process::Command;
 
 use itertools::Itertools;
-use jj_lib::config::ConfigFile;
 use jj_lib::config::ConfigLayer;
 use jj_lib::config::ConfigLoadError;
 use jj_lib::config::ConfigNamePathBuf;
@@ -34,10 +33,6 @@ use regex::Regex;
 use thiserror::Error;
 use tracing::instrument;
 
-use crate::command_error::user_error;
-use crate::command_error::user_error_with_message;
-use crate::command_error::CommandError;
-
 // TODO(#879): Consider generating entire schema dynamically vs. static file.
 pub const CONFIG_SCHEMA: &str = include_str!("config-schema.json");
 
@@ -427,35 +422,6 @@ pub fn parse_config_args(toml_strs: &[ConfigArg]) -> Result<Vec<ConfigLayer>, Co
         .try_collect()
 }
 
-pub fn write_config_value_to_file(
-    key: &ConfigNamePathBuf,
-    value: toml_edit::Value,
-    path: &Path,
-) -> Result<(), CommandError> {
-    // TODO: Load config layer by caller. Here we use a dummy source for now.
-    let mut file = ConfigFile::load_or_empty(ConfigSource::User, path)?;
-    file.set_value(key, value)
-        .map_err(|err| user_error_with_message(format!("Failed to set {key}"), err))?;
-    file.save()?;
-    Ok(())
-}
-
-pub fn remove_config_value_from_file(
-    key: &ConfigNamePathBuf,
-    path: &Path,
-) -> Result<(), CommandError> {
-    // TODO: Load config layer by caller. Here we use a dummy source for now.
-    let mut file = ConfigFile::load_or_empty(ConfigSource::User, path)?;
-    let old_value = file
-        .delete_value(key)
-        .map_err(|err| user_error_with_message(format!("Failed to unset {key}"), err))?;
-    if old_value.is_none() {
-        return Err(user_error(format!(r#""{key}" doesn't exist"#)));
-    }
-    file.save()?;
-    Ok(())
-}
-
 /// Command name and arguments specified by config.
 #[derive(Clone, Debug, Eq, PartialEq, serde::Deserialize)]
 #[serde(untagged)]